Joint implant extraction and placement system and localization device used therewith

ABSTRACT

An implant localization device includes a coupler and a positioning system. The coupler is configured to removably engage an implant component to fix the positioning system in space relative to the implant component. The positioning system is in communication with a centralized computing system, whereby, due to the fixed spatial relationship between the positioning system and the implant component, via the coupler, and determinable changes in movement relative to a registered starting point, the centralized computing system is able to calculate a real-time position and orientation of the implant component. The centralized computing system is configured to synthesize data from a joint templating software program, a CAD software program, and the positioning system to provide real-time positional and orientation data to assist with extraction and placement of the implant component. Robotics and reference markers may be used to further automate and/or enhance the accuracy and efficiency of the system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/025,792 filed on May 15, 2020, entitled “JOINT IMPLANT PLACEMENTAND EXTRACTION SYSTEM”, the entire disclosure of which is incorporatedby reference herein.

BACKGROUND OF THE INVENTION 1. Field of Invention

The present invention relates to systems and apparatuses for automatingthe extraction and placement of joint implants in joint replacementprocedures.

2. Description of Related Art

Implant Extraction

Joint revision surgery, whether for a hip, a knee, a shoulder, an ankle,an elbow, or any other joint that is a candidate for revision surgery,is a procedure in which the surgeon removes a previously implantedartificial joint, i.e., a prosthesis, and replaces it with a newprosthesis. The first stage in joint revision surgery is the removal ofthe old prosthesis. Extraction of the joint components is often the mostdifficult aspect of the revision procedure and ultimately dictates whatis required for the final reconstruction.

Revision surgery typically involves the use of a cutting tool, such as ahigh-speed burr-tip rotary tool, a ballistic chisel powered bycontrolled bursts of pressurized nitrogen, manual osteotomes or flexibleSteinmann pins drilled around the prosthesis. These tools are used tobreak up pieces of cement or bone from an implanted prosthesis, but canalso be used to loosen a prosthesis that was held in place by a pressfit. The surgeon generally uses these tools blindly, i.e., withoutreal-time feedback of the location of the tool relative to theprosthesis, in an attempt to disrupt the interface between thebone/cement and the prosthesis. If the surgeon is unable to adequatelydisrupt the interface between the bone/cement and the prosthesis usingthe cutting tools, then an osteotomy may need to be performed tofacilitate prosthesis removal. For example, hip revision surgery mayrequire an extended trochanteric osteotomy (ETO), whereby the femur iscut in half, using a hand saw or burr to facilitate removal of theimplant, which results in significant morbidity to the patient andincreased operating time.

Some prosthetic components, such as a hip cup, oftentimes require theuse of a slap hammer, or similar device, coupled to a threaded holein/on the prosthetic component and/or a manual cutting tool forextraction. One such device is disclosed in U.S. Pat. No. 7,998,146B2 toAnderson. U.S. Pat. No. 7,998,146B2 discloses a hip cup extractionapparatus comprising a shaft, a handle, a semicircular cutting blade, aspring-loaded latching member, and a head for removing a hip cup from apelvic bone. The head is inserted into the hip cup. Force may then beapplied to the hip cup extraction apparatus in order to drive thesemicircular cutting blade into the pelvic bone. The hip cup extractionapparatus may then be rotated or pivoted such that the semicircularcutting blade passes completely around the hip cup.

Currently, all technologies for extraction of prostheses, particularlywith regard to cutting, are performed manually. As with any procedureperformed by a human, there are a number of issues that can arise withmanual extraction. These issues include, but are not limited to: (i)time-consuming procedures that increase the patient's susceptibility tosurgical complications; (ii) bone loss due to the surgeon's inability tonavigate with absolute accuracy and precision, resulting from thesurgeon's inability to determine the precise location/contour of theimplant; and (iii) bone fracture from stresses on the bone(s), e.g.,from the use of a slap hammer and/or a manual chisel/blade, etc.

Implant Placement

When placing an implant, either in a primary joint replacement procedureor a joint revision procedure, care must be taken to properly seat theimplant to, among other things, restore normal joint mechanics. Forexample, one of the goals of femoral stem placement in hip replacementprocedures includes restoration of normal hip mechanics, which requiresconsideration of (i) medial offset, (ii) leg length, i.e., verticalheight, (iii) femoral anteversion, and (iv) center of rotation. Verticalheight is determined by where the center of the femoral head sits, i.e.,the center of rotation. Vertical height can be affected if the stem isnot accurately positioned, e.g., if it is set too deep or, conversely,not deep enough into the femur. Vertical height can be adjusted by thestem vertical position in the femur as well as using modular femoralheads with different diameters and neck lengths. However, adjusting thevertical height by using femoral heads will likewise affect themedial/lateral offset, which may result in complications includingdiscomfort to the patient or possible instability of the total hiparthroplasty resulting in dislocation. Thus, proper placement of thestem is critical for stem fixation as well as ensuring that the properfemoral head is used, thereby mitigating incidence ofmalalignment/complications.

To prevent component malposition and a postoperative leg lengthdiscrepancy, surgeons typically combine x-rays of the patient's hip withoverlay schematics of the hip replacement prosthesis. This process isknown as templating and allows the surgeon to make an initialdetermination of the size of the implants needed at the time of surgery,the size of the leg length discrepancy needing correction, and how muchbone that will need to be removed intraoperatively. However, it isdifficult to achieve accurate positioning of implants and assess thenumerical value of implant positioning in primary hip replacementprocedures using conventional methods. In an attempt to address thesedeficiencies, surgeons are now using computer-guided systems androbotics to help confirm the position and size of the hip replacementimplants during surgery. The computer-guided templating and navigationsystems show the patient's bony anatomy on-screen to help guide thesurgeon in positioning the implants. In cases in which robotics areutilized, the navigation system guides the robotic arm/surgeon, in anautomated or semi-automated fashion, with implant placement.Additionally, sensor arrays are used in primary implant procedures tolocalize the bone for the navigation system to ensure the positioning ofthe implant matches the templated parameters desired by the surgeon inreal-time.

Fluoroscopy is often used in conjunction with, or as an alternative to,computer-guided/navigation systems to help guide surgeons during implantplacement. To ensure proper depth of the implant, intermittentfluoroscopy scans, e.g., x-rays, must be performed intraoperatively toanalyze current placement of the implant and determine what adjustmentsmay be necessary to properly seat the implant. The intermittent scansare not performed in a way that they can be viewed in real-time whileperforming the procedure without placing the surgical staff at risk forexcessive x-ray/fluoroscopic exposure. Fluoroscopy is also limited bythe 2-D spatial orientation, parallax (which can alter the accuracy ofthe images), patient mal-positioning (which can make high quality imagesmore difficult to obtain in the intra-operative theater), anddifficulties identifying good bony landmarks on both femurs and thepelvis. Thus, the surgeon is unable to ensure precise and accurateseating of the implant in real-time.

The foregoing discussion demonstrates the current barriers in implantplacement accuracy in total hip replacement. However, it should be notedthat any total joint replacement surgery, whether for a knee, ashoulder, an ankle, an elbow, or any other joint is subject to the samechallenges with recreating the joint mechanics and implant placement.

Based on the foregoing, there is a need in the art for automated systemsfor extracting and placing joint implants in primary and revisionprocedures that provide real-time positioning data, thereby allowingsuch procedures to be performed in a more efficient manner withincreased precision and accuracy, decreasing radiation exposure, whilemitigating bone loss and, hence, undue stress to the patient and thelikelihood of surgical complications.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, the system forextracting and placing joint implants includes a centralized computingsystem, a joint templating software program configured to compare jointscans with overlay schematics of an implant component, a CAD softwareprogram configured to analyze a computer-generated design of the implantcomponent, and a localization device for localizing an implant componentin space. The localization device includes a coupler and a positioningsystem, wherein the coupler is configured to removably engage theimplant component (e.g., via engagement with the trunnion on a femoralstem, a threaded insertion hole on an acetabular shell, insertion pointson femoral/tibial components in total knee arthroplasty, etc.) to fixthe positioning system in space, in a known position and orientation,relative to the implant component. The positioning system comprises oneor more sensors, e.g., line-of-sight sensors, which are registered withthe centralized computing system pre-operatively or intra-operatively,whereby the centralized computing system is able to use data from thepositioning system to determine changes in position and orientation ofthe positioning system, relative to its starting position andorientation, thereby allowing the computing system to calculate areal-time position and orientation of the positioning system, whereby,due to the fixed spatial relationship between the positioning system andthe implant component, via the coupler, the centralized computing systemis able to calculate a real-time position and orientation of the implantcomponent. The centralized computing system is configured to synthesizedata from the joint templating software program, the CAD softwareprogram, and the positioning system to provide real-time position andorientation data regarding the implant component to assist withextraction and placement of the implant component.

In an embodiment, the system includes a robotic arm in communicationwith the centralized computing system. The robotic arm is registeredwith the centralized computing system pre-operatively orintra-operatively. Once registered, the centralized computing system isable to determine the real-time position and orientation of the roboticarm. Means for tracking the position and orientation of robotics areknown to those skilled in the an and can be carried out in a number ofways. Any such means can be used with the present invention withoutdeviating from the scope of the invention. The robotic arm is configuredto execute instructions received from the centralized computing system,wherein the instructions are based on information including, but notlimited to, the synthesized data, i.e., the combined data from the jointtemplating software program, the CAD software program, and thepositioning system.

In an embodiment, the robotic arm includes a cutting tool configured tofacilitate extraction of the implant component.

In an embodiment, the system includes one or more reference markers. Thereference marker(s) is/are registered with the centralized computingsystem, whereby the centralized computing system is able to monitor thereal-time position and orientation of the references marker(s). In suchan embodiment, the instructions transmitted to the robotic arm from thecentralized computing system also include the real-time position andorientation of the reference marker(s). In such an embodiment, referencemarker(s) are analyzed by the centralized computing system to track thereal-time orientation and position of the bones and other anatomicstructures relative to the other components in the system (e.g. roboticarm, coupler/implant, etc.)

In an embodiment, the robotic arm comprises an insertion tool configuredto facilitate placement of the implant component.

In an embodiment, the system includes a probe configured to registervirtual points, which may include reference marker(s) (reference markerswould need to be registered with a probe in applications where thereference markers do not have a tracking device, e.g. line-of-sightarray, integrated into the reference markers for tracking by centralizedcomputing system), points on bone, points on implants, etc., with thecentralized computing system. Once registered, the centralized computingsystem is able to determine the real-time position and orientation ofthe registered virtual points.

In an embodiment, the centralized computing system is configured toanalyze the real-time position of the coupler relative to the real-timeposition of the reference marker(s) (and/or virtual reference points),i.e. triangulation, to determine the real-time joint parameters of theimplant component. (e.g., hip vertical position, leg length, medialoffset, center of rotation etc. in hip applications; joint line, implantrotation, varus/valgus alignment, etc. in knee applications, etc.)

In various embodiments, the coupler may be any suitable configurationthat allows it to releasably couple to the implant component to fix thepositioning system in space relative to the implant component. Anon-exhaustive list of example configurations for the coupler include asleeve, a clamp, and a rod.

In an embodiment, the positioning system is integrally formed as part ofthe coupler, whereby the positioning system and the coupler are asingle, unitary component. Alternatively, in an embodiment, thepositioning system is removably coupled to the coupler. When coupled,the positioning system and the coupler are configured to maintain afixed position and orientation relative to one another until decoupled.

In an embodiment, the positioning system includes an inertial sensor. Invarious embodiments, the inertial sensor is an accelerometer, agyroscope, or a combination accelerometer/gyroscope.

In an embodiment, the positioning system includes a sensor array (i.e.visual array).

In an embodiment, the system includes a database of implant componentdesigns, wherein the CAD software program is configured to analyze animplant component design selected by a user from the database and renderaccurate implant dimension data for use by the centralized computingsystem.

In an embodiment, if dimension data is not available for the implant,the CAD software program is also able to synthesize data from virtuallyregistered points, using a probe, on implant components to extrapolatethe contours of the implant for dimension data of the implant componentfor use by the centralized computing system.

The present system monitors movement of the implant component bymonitoring changes in the position and orientation of the implantcomponent—determined by the centralized computing system, based onchanges in the position and orientation of the localization device astracked by the centralized computing system. Based on changes in theposition and orientation of the localization device, relative to theinitial position and orientation of the localization device (establishedwhen registering the localization device with the centralized computingsystem), and the fixed spatial relationship between the localizationdevice and the implant component, the system can determine the real-timeposition and orientation of the implant component in 3-dimensionalspace.

Similarly, based on changes in the position and orientation of thesystem components (robotic arm, reference markers/reference points,etc.), relative to their respective baseline, i.e., starting, positionsand orientations determined at the time of registration of the systemcomponents with the centralized computing system, the system candetermine the real-time position and orientation of each of the systemcomponents, e.g., the cutting tool of the robotic arm, in 3-dimensionalspace. By comparing the real-time position and orientation of theimplant with the real-time position and orientation of the systemcomponents (via positioning/mapping software, for example), the systemcan determine the real-time spatial relationship between/among thesystem components, anatomic structures, and the implant component, i.e.triangulation.

The system's ability to synthesize the position and orientation data ofthe implant component and the system components with thedimensional/contour data of the implant component (provided by the CADsoftware) and the placement/sizing/fitment data (provided by thetemplating software) optimizes the overall accuracy and precision of thepresent system when extracting and placing implant components as well asrecreating or restoring desired joint parameters.

This system can be used to facilitate (i) implant extraction in revisionprocedures, (ii) implant placement following implant extraction inrevision procedures, and (iii) implant placement in primary jointreplacement procedures, each of which are summarized below.

Joint Replacement Implant Extraction Application

In an embodiment, the present system is used to extract implantcomponents in revision procedures. Due to the fixed spatial relationshipbetween the positioning system and the implant component, via thecoupler, the centralized computing system is able to monitor, inreal-time, the movement and, hence, the spatial orientation and positionof the implant component—based on data received by the centralizedcomputing system from the positioning system. The computerized jointsoftware/templating system combines imaging (e.g., x-rays, CT scan,etc.) of the patient's bony anatomy with overlay schematics of thereplacement prosthesis to aid in the joint reconstruction. Thecentralized computing system synthesizes the computerized jointsoftware/templating system data, the CAD implant data, the positioningsystem data (regarding the real-time position and orientation of theimplant component in space), and reference markers/points data, toensure absolute accuracy and precision of the dimensionalaspects/contour of the implant component, the implant component positionand orientation in space, and the patient's bony anatomy to aid in theextraction and reconstruction process.

In an embodiment, the CAD software program is configured to analyze animplant component design selected by a user from the database ofimplants, allowing the centralized computing system to provide accurateimplant dimensional data and instructions to the robotic arm. If animplant is not found in the database, the visible surface of the implant(i.e., the contours and dimensions) can be determined real-time using aprobe, with a positioning sensor, e.g., a line-of-sight or otherwireless sensor in communication with the centralized computing system,affixed to it, whereby the user “paints” the surface of the implant toprovide reference points for the CAD program to extrapolate the contourand dimensional data for the implant.

In various embodiments, one or more reference points (e.g., the shoulderof the femoral implant, identification of ingrowth/ongrowth surfaces, athreaded insertion hole on the shoulder, etc.), in addition to thecoupler, are registered on the implant to increase the accuracy of theimplant position and orientation in space. The reference points may bevirtually placed on the implant using a probe in communication (wired orwireless) with the centralized computing system. Alternatively, thereference points may be physically attached to the implant, whereby thereference points are in communication (wired or wireless) with thecentralized computing system. The centralized computing system thenguides the robotic arm (which may be automated or semi-automated) to cutthe implant from the bone/cement interface with absolute accuracy andprecision based on the precise measurements and real-time position andorientation of the implant, as determined by data provided by the CADsoftware program, the joint software/templating system, and thepositioning system.

The system's ability to determine the real-time spatial relationshipbetween/among the system components, e.g., the robotic arm, etc., andthe implant component allows the centralized computing system toinstruct the robotic arm in real-time in response to changingconditions. For example, if the position and/or orientation of theimplant is altered during the extraction procedure, the robotic arm willmake the necessary adjustments in real-time, in accordance with theinstructions from the centralized computing system, to ensure absoluteaccuracy and precision in extracting the implant. Since the dimensionsof the implant and its position and orientation is “known” and trackedby the centralized computing system, the robotic arm cutting tool canmake the cut directly adjacent to the implant or a predetermineddistance from the bone/implant interface (e.g. make the cut with 1 mmbone remaining on the implant, etc.)

The fixed spatial relationship between the positioning system andimplant component, combined with real-time position and orientation dataof the positioning system, as determined by the centralized computingsystem (which allows real-time position and orientation of the implantcomponent to be determined), eliminates the need to insert bone pins oraffix reference points to the bone to localize the implant forextraction (bone pins/reference markers are only required forimplantation of components). The fixed spatial relationship between thepositioning system and implant component, combined with real-timeposition and orientation data of the positioning system, as determinedby the centralized computing system (which allows real-time position andorientation of the implant component to be determined), can also beutilized with the same degree of accuracy in applications where anosteotomy is required to aid in the extraction of the implant, e.g., anextended trochanteric osteotomy (ETO), etc.

Joint Replacement Implant Placement—Following Extraction

In an embodiment, the position data of the original/extracted implantcan be useful for reconstruction of the joint following implantextraction, e.g., with placement of the revision components to recreateor correct the original joint mechanics. In such an embodiment, bonereference markers (e.g., a unicortical screw, a cortical button, asuperficial registration point, visual array, small drill hole in bone,etc.) are placed in the bones prior to affixing the localization device(i.e., the coupler and positioning system) to the implant. The referencemarkers are used to reference the position of the original implant(before extraction) in relation to the bones (e.g., femur andacetabulum/pelvis in hip applications, femur and tibia in kneeapplications, etc.). The reference markers can then be registered withthe centralized computing system so that the original joint parameters(e.g., hip vertical position, leg length, medial offset, center ofrotation etc. in hip applications; joint line, implant rotation,varus/valgus alignment, etc. in knee applications, etc.) can bedetermined/calculated. Once the bone reference markers are registeredand data is collected on the original implants (based on the spatialposition of the implants relative to the bone reference markers),implant extraction can occur, as described above.

Additionally, bony registration and mechanical axis registration may berequired after implant extraction to compare against the bony referencemarkers placed prior to implant extraction. The bone reference markersremain in the bone and can then be used as reference points toreconstruct the joint parameters with the coupler attached to therevision implants. This aids in placement of the revision implantcomponents with real-time feedback on important joint replacementparameters in comparison to the original implants (e.g., verticalheight, leg length, offset, anteversion, etc. in hip applications; jointline, implant rotation, varus/valgus alignment, etc. in kneeapplications). This real-time feedback on important joint replacementparameters allows the surgeon to adjust the modular features of theimplants needed to correct the joint parameters prior to trialing theconstruct. For example, in hip revision surgery the revision femoralcomponent can be placed in the bone and the localization device can thenbe attached to the component trunnion (trial or final) to register thecenter of rotation (which would also account for offset, leg length)against the reference markers. If, for example, the system found therevision components' new center of rotation position to result in aconstruct that is 3 mm short in leg length and offset from the originalextracted implant's center of rotation position, the surgeon wouldimmediately know the specific modular head needed to move the new centerof rotation to recreate the original hip mechanics, this would alsoallow the surgeon to know the changes that would alter the originaljoint mechanics if desired. This could all be done prior to reducing thehip and trialing the construct. In current practice, the surgeon wouldneed to reduce the hip and trial multiple different head options todetermine this information, increasing surgical time and tissue traumawith repeated reductions and dislocations. Additionally, an x-ray orfluoroscopic image is often taken to help determine the correct leglength, offset, etc. which increases the radiation risk to all personalinvolved. As another example, in a knee application, this system wouldallow the surgeon to know the original joint line position (e.g., distalfemoral implant position, gap balance, etc.) as referenced by the datafrom the extracted implant. Following extraction, the surgeon canreference the remaining distal femoral bone cuts (e.g., with a probe,etc.) against the bone reference markers and adjust distal augments orpolyethylene insert size to recreate the joint line in real-time priorto trialing the construct. This would increase both efficiency of thereconstruction procedure as well as accuracy.

This system can be used with or without robotic assistance. In roboticapplications, the robotic arm could be used to cut/prepare/broach thebone to the correct contour to match the revision components and basedon the data collected prior to implant removal. Modular selection ofimplants to build the revision components would proceed as describedabove and the robotic arm would assist with implantation of theimplants. In some embodiments, the robotic arm may not aid in implantplacement. In non-robotic applications, following implant extraction,the bone would be prepared by traditional methods, e.g., using cuttingblocks/jigs/broaches, manual cutting, etc., to prepare the bone forrevision components, but the modular selection of implants would proceedas described above.

Although specific examples are discussed herein, one skilled in the artwould understand and appreciate that this application is not limited tothese specific examples and is applicable to the other modular aspectsof revision and primary joint replacement components (e.g., modularbodies of femoral components, different acetabular liners, differentfemoral neck angles/offsets, etc. in the hip model; knee joint line,distal/posterior femoral condyle augments, component rotation, tibialcomponent position/slope, polyethylene liner thickness, etc. in the kneemodel; etc.).

Primary Hip Replacement Femoral Component Insertion Application

In an embodiment, the present system can be used for placing jointimplants in primary applications, which can be done with or withoutrobotic assistance.

Prior to performing the femoral neck cut, bone reference markers (e.g.,a cortical button, a superficial registration point, etc.) are placedand a fluoroscopy shot is taken of the hip including the bone referencemarkers. This image is used to create a real-time template on thecomputerized joint software/templating program. The reference markersare a predetermined size to allow appropriate scaling for the template.The remainder of the hip replacement procedure proceeds based on theintra-operative template (e.g., acetabular component placement, femoralbone preparation, etc.) until the femoral trial component (e.g., broachwith trial neck, trial femoral component, final femoral component, etc.)is inserted and utilized for trialing of the hip replacement. Once thetrial component has been placed in the femur the localization device isattached to the femoral trunnion. The positioning system is thenreferenced against the bone reference markers to determine the real-timehip center position in relation to the real-time template. This allowsthe surgeon to adjust implant position as well as select the correctmodular femoral head to recreate the native center of rotation, leglength, offset, etc. in real-time and prior to trialing. The implantthen can be trialed with the correct modular components. This system canagain be used to confirm correct placement of the final femoral stem andselection of the final modular head. This system increases speed andefficiency of implant modularity selection. It also recreates the hipparameters with absolute precision and accuracy.

The foregoing discussion regarding implant extraction and placement inhip revision procedures and implant placement in primary hip replacementprocedures is provided in a non-limiting manner, i.e., for illustrativepurposes only, to demonstrate use of the present system in revision andprimary joint replacement procedures. One skilled in the art wouldunderstand that the present system can be similarly used in revision andprimary joint replacement procedures for any joint that is a candidatefor such procedures.

The foregoing, and other features and advantages of the invention, willbe apparent from the following, more particular description of thepreferred embodiments of the invention, the accompanying drawings, andthe claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention, the objectsand advantages thereof, reference is now made to the ensuingdescriptions taken in connection with the accompanying drawings brieflydescribed as follows.

FIG. 1 shows the joint implant extraction and placement system in usewith a femoral stem, according to an embodiment of the presentinvention;

FIG. 2 shows the joint implant extraction and placement system in usewith an acetabular cup, according to an embodiment of the presentinvention;

FIG. 3 shows the joint implant extraction and placement system in usewith a total knee femoral component, according to an embodiment of thepresent invention;

FIG. 4 shows the joint implant extraction and placement system in usewith a total knee tibial component, according to an embodiment of thepresent invention;

FIG. 5 is a flow chart showing a method of joint replacement implantextraction, according to an embodiment of the present invention;

FIG. 6 is a flow chart showing a method of joint replacement implantplacement following extraction, according to an embodiment of thepresent invention; and

FIG. 7 is a flow chart showing a method of primary hip replacementfemoral component insertion, according to an embodiment of the presentinvention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments;however, the order of description should not be construed to imply thatthese operations are order-dependent.

The description may use perspective-based descriptions such as up/down,back/front, left/right, and top/bottom. Such descriptions are merelyused to facilitate the discussion and are not intended to restrict theapplication of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalcontact with each other. “Coupled” may mean that two or more elementsare in direct physical contact. However, “coupled” may also mean thattwo or more elements are not in direct contact with each other, but yetstill cooperate or interact with each other.

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” means (A), (B), or (A and B). For the purposes ofthe description, a phrase in the form “at least one of A, B, and C”means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).For the purposes of the description, a phrase in the form “(A)B” means(B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments, are synonymous.

Preferred embodiments of the present invention and their advantages maybe understood by referring to FIGS. 1-7 wherein like reference numeralsrefer to like elements.

This system can be used to facilitate (i) implant extraction in revisionprocedures, (ii) implant placement following implant extraction inrevision procedures, and (iii) implant placement in primary jointreplacement procedures. The following description provides illustrative,non-limiting examples of how the present system can be used in each ofthese applications.

Joint Replacement Implant Extraction

With reference to FIG. 1, coupler 10 is configured to mount to animplant component (i.e., via engagement with the trunnion on a femoralstem) to fix positioning system 15 in a pre-determined position andorientation, relative to the implant component, so that the entirety ofthe implant component can be localized in space based on this fixedrelationship. Based on changes in the position and orientation ofpositioning system 15, relative to the initial position and orientationof positioning system 15 (established when registering positioningsystem 15 with centralized computing system 45 preoperatively orintraoperatively), and the fixed spatial relationship betweenpositioning system 15 and the implant component, via coupler 10,centralized computing system 45 is able to determine the real-timeposition and orientation of the implant component in 3-dimensionalspace.

In an embodiment, as shown in FIG. 1, coupler 10 is a sleeve thatreceives trunnion 20, just as the matching female taper of a modularfemoral head would. Coupler 10 is configured to engage trunnion 20 usinga friction fit, snap fit, or any other suitable releasable engagementmechanism known in the art (e.g., a Morse taper, etc.), whereby, uponengagement, coupler 10, positioning system 15, and femoral stem 5 arefixed, i.e., immobilized, relative to one another. Upon engagement,coupler 10 remains firmly secured in place on trunnion 20 until manuallyremoved.

In an embodiment, positioning system 15 is integrally formed as part ofcoupler 10, i.e., positioning system 15 and coupler 10 are a single,unitary component. Alternatively, positioning system 15 and coupler 10are separate components, whereby positioning system 15 is removablycoupled to coupler 10. When coupled, positioning system 15 and coupler10 are configured to maintain a fixed orientation relative to oneanother until decoupled. Coupler 10 may be coupled to the implantcomponent at the time of manufacturing. Alternatively, coupler 10 may becoupled to the implant component by the surgeon or staff at the time ofsurgery.

Positioning system 15 includes one or more sensors configured todetermine real-time position and orientation of an implant componentcoupled to positioning system 15. For example, in an embodiment,positioning system 15 includes an accelerometer for measuring theorientation of femoral stem 5 in a stationary state. In a furtherembodiment, positioning system 15 also includes a gyroscope tosupplement the information provided by the accelerometer. Namely, thegyroscope adds an additional dimension to the information supplied bythe accelerometer by tracking rotation or twist of a non-stationary fernoral stern 5. In an embodiment, as an alternative to the accelerometerand gyroscope, positioning system 15 includes an array ofvisual/line-of-sight sensors (e.g., infrared arrays, etc.) configured todetermine the real-time position of femoral stem 5, relative to theremaining system components, e.g., centralized computing system 45 androbotic arm 50, intraoperatively.

Once coupler 10 engages trunnion 20, positioning system 15 moves insynchrony with femoral stem 5. Thus, if a patient/surgeon were to movethe leg during the revision procedure, positioning system 15 wouldundergo the same movement to the exact degree as femoral stem 5, therebyenabling centralized computing system 45 to determine, based onreal-time data from positioning system 15, real-time changes in positionand orientation of femoral stem 5. Additionally, one or more referencepoints (e.g., the shoulder of the implant, insertion threads,ingrowth/ongrowth surface, etc.) on the implant (in addition to coupler10) may be used in conjunction with the data provided by positioningsystem 15 to improve accuracy of the system. For example, in anembodiment, virtual reference points are registered with centralizedcomputing system 45 using probe 95 (or other similar device known in theart) without physical attachment to the implant. In such an embodiment,probe 95 (or other similar device) is in communication, wired orwireless, with centralized computing system 45 and is used to interactwith the implant to designate reference point(s) that are communicatedto centralized computing system 45. Alternatively, reference points(e.g., line-of-sight sensors, etc.) may be physically connected to theimplant (e.g., threaded into an insertion hole in femoral stem 5, etc.),whereby the reference points are in wireless communication withcentralized computing system 45.

Positioning system 15 is in communication, wired or wireless (e.g., viawireless transmitter, infrared line-of-sight sensor(s), etc.), withcentralized computing system 45. Computing system 45 receives andprocesses data received from positioning system 15. This data iscombined with data received from a computer-aided design, i.e., CAD,software program that analyzes computer-generated designs, includingdimensional aspects, of the femoral stem 5. Centralized computing system45 also includes a database of CAD designs with precise dimensionalaspects of various femoral stems 5. This allows a user, in preparationfor a revision procedure, to select an implant, e.g., by manufacturer,serial number, model number, etc., from the database. Once selected, thesoftware is able to provide exact dimensional specifications of theimplant. In various embodiments, centralized computing system 45 alsoincludes a computerized joint software/templating system that combinesimaging (e.g., x-rays, CT scans, etc.) of the patient's bony anatomywith overlay schematics of the replacement prosthesis (i.e., templating)to further aid in the joint reconstruction.

Robotic arm 50 (or any form of robotic assisted joint replacementapplication) is in communication, wired or wireless (e.g., via wirelesstransmitter, infrared line-of-sight sensor(s), etc.), with centralizedcomputing system 45. An initial baseline position and orientation ofrobotic arm 50 is registered with centralized computing system 45 priorto a procedure (or intra-operatively). Thereafter, centralized computingsystem 45 tracks all movement of robotic arm 50, e.g., usingline-of-sight sensors, inertial sensors, etc. Based on changes in theposition and orientation of robotic arm 50, relative to its respectivebaseline position and orientation, centralized computing system 45 candetermine the real-time position and orientation of robotic arm 50.

Robotic arm 50 may be fully automated or semi-automated. In anembodiment, whereby robotic arm 50 is fully automated, robotic arm 50operates independent of physical assistance/intervention from a human,based on instructions provided by the centralized computing system 45.Conversely, in an embodiment, whereby robotic arm 50 is semi-automated,robotic arm 50 is, at least in-part, physically, i.e., manually, guidedby a human, subject to pre-defined boundaries set by the centralizedcomputing system 45, to carry out a defined task. Cutting tool 55, e.g.,a burr-tip rotary tool, an ultrasonic reciprocating blade, chisel,flexible pin, blade, water jet, etc., is attached to robotic arm 50. Thereal-time position and orientation of femoral stem 5 is constantlydetermined by positioning system 15 and tracked by centralized computingsystem 45. This information, along with the dimensional aspects offemoral stem 5, as provided by the CAD software program, is processed bycentralized computing system 45. Centralized computing system 45 thencommunicates instructions for cutting around femoral stem 5, based on aset of parameters output by the CAD software program and a real-timeposition and orientation of femoral stem 5, as localized by positioningsystem 15. By providing these calculated instructions in real-time,robotic arm 50 is able to carve femoral stem 5 from the patient's femurwith maximized precision and accuracy (similar to that of a CNC router),increased efficiency and minimal bone loss, thus mitigating undue stressand potential for surgical complications to the patient. Further,because the instructions to robotic arm 50 are based, at least in-part,on real-time positional data of the implant, robotic arm 50 is able torespond to movements of femoral stem 5 in real-time without losingaccuracy and precision.

With reference to FIG. 2, the joint implant extraction system is shownin use with hip cup 60. Coupler 65 is rod-shaped, whereby at least oneend of coupler 65 is threaded and is configured to releasably engagecentral aperture/orifice 70 of hip cup 60 by threaded engagement. Theopposite end of coupler 65 may also be threaded, or otherwiseconfigured, to releasably engage an object, such as handle or extractiontool (e.g., a slap-back member, pneumatic extraction device, malletimpaction plate, robotic arm etc.) to assist with extraction of hip cup60. Just as described above in relation to coupler 10, positioningsystem 15 is connected to or, alternatively, integrated within, coupler65. Once engaged, coupler 65 is secured into position in hip cup 60,whereby hip cup 60, coupler 65, and positioning system 15 are fixed,i.e., immobilized, relative to one another, such that the position andorientation of hip cup 60 is determinable, real-time, by centralizedcomputing system 45, based on the real-time data received by centralizedcomputing system 45 from positioning system 15.

In embodiments in which robotic arm 50 is guided by navigation only(e.g. line-of-sight array, etc.), in response to instructions fromcentralized computing system 45, as determined based on implant datareceived from the CAD software program and positioning system 15,robotic arm 50 moves independently of coupler 65 to facilitate excisionof hip cup 60 using cutting tool 55. Alternatively, robotic arm 50 canattach directly to coupler 65 (rod shaped) and move along the length ofcoupler 65 to localize hip cup 60, whereby positioning system 15 may notbe required.

In an embodiment, as shown in FIG. 2, the inner radius of curvature ofcutting tool 55, i.e., that which corresponds to the edge of cuttingtool 55 that is in physical communication with hip cup 60 during theexcision/extraction procedure, is complementary to the exterior radiusof curvature of hip cup 60. If CAD data is not available or cup size isunknown, probe 95 can be used to “paint” the surfaces of hip cup 60 toprovide real-time implant dimension data to the centralized computingsystem 45. Probe 95 includes a positioning system (e.g., line-of-sightsensor) configured to communicate with centralized computing system 45.As the user “paints” the surface of the implant, data points arecommunicated to centralized computing system 45. The CAD program thenuses the data to extrapolate contour and dimensional data for theimplant. Depending on the software, painting may include, for example,shading/painting a defined portion of the hip cup 60, the entire surfaceof hip cup 60, or outlining the surfaces of hip cup 60.

With reference to FIG. 3, the joint implant extraction system is shownin use with total knee femoral component 80. Coupler 75 is shaped like avice grip, whereby coupler 75 clamps each side of the implant andreleasably engages femoral component insertion slot 77 of total kneefemoral component 80 by pressure clamp engagement. The opposite end ofcoupler 75 may also be threaded, or otherwise configured, to releasablyengage an object, such as handle or extraction tool (e.g., a slap-backmember, pneumatic extraction device, mallet impaction plate, robotic armetc.) to assist with extraction of total knee femoral component 80. Justas described above, in FIG. 1., relation to coupler 10, positioningsystem 15 is connected to or, alternatively, integrated within, coupler75. Once engaged, coupler 75 is secured into position in total kneefemoral component 80 at notch 77, whereby total knee femoral component80, coupler 75, and positioning system 15 are fixed, i.e., immobilized,relative to one another, such that the position and orientation of totalknee femoral component 80 is determinable, real-time, by centralizedcomputing system 45, based on the real-time data received by centralizedcomputing system 45 from positioning system 15. In response toinstructions from centralized computing system 45, as determined basedon implant data received from the CAD software program and positioningsystem 15, robotic arm 50 moves independently of coupler 75 inembodiments in which robotic arm 50 is used to facilitate excision oftotal knee femoral component 80 using cutting tool 55. If CAD data isnot available, probe 95 can be used to “paint” the surfaces of the totalknee femoral component 80 to provide real-time implant dimension data tothe centralized computing system 45 to synthesize and extrapolate thecomplete femoral component 80 dimensions.

With reference to FIG. 4, the joint implant extraction system is shownin use with total knee tibial component 100. Coupler 105 is shaped likea vice grip or matches tibial component locking mechanism 110, wherebycoupler 105 clamps to total knee tibial component 100 locking mechanism(or sides of implant) 110 and releasably engages tibial componentlocking mechanism (or sides of component) 110 of total knee tibialcomponent 100 by pressure clamp engagement. The opposite end of coupler105 may also be threaded, or otherwise configured, to releasably engagean object, such as handle or extraction tool (e.g., a slap-back member,pneumatic extraction device, mallet impaction plate, robotic arm etc.)to assist with extraction of total knee tibial component 100. Just asdescribed above, in FIG. 1., relation to coupler 10, positioning system15 is connected to or, alternatively, integrated within, coupler 105.Once engaged, coupler 105 is secured into position in total knee tibialcomponent 100, whereby total knee tibial component 100, coupler 105, andpositioning system 15 are fixed, i.e., immobilized, relative to oneanother, such that the position and orientation of total knee tibialcomponent 100 is determinable, real-time, by centralized computingsystem 45, based on the real-time data received by centralized computingsystem 45 from positioning system 15. In response to instructions fromcentralized computing system 45, as determined based on implant datareceived from the CAD software program and positioning system 15,robotic arm 50 moves independently of coupler 105 in embodiments inwhich robotic arm 50 is used to facilitate excision of total knee tibialcomponent 100 using cutting tool 55. If CAD data is not available, probe95 can be used to “paint” the surfaces of the total knee tibialcomponent 100 to provide real-time implant dimension data to thecentralized computing system 45 to synthesize and extrapolate thecomplete tibial component 100 dimensions.

The flow chart depicted in FIG. 5 summarizes the method of jointreplacement implant extraction using the present system. The methodoutlined in FIG. 5 can be applied to any joint implant component and isprovided for illustrative purposes, according to an embodiment of thepresent invention. Therefore, it should not be interpreted as beinglimiting to any particular application.

Joint Replacement Implant Placement Following Extraction

In addition to the extraction of implants in revision surgeries, thepresent invention can also be used to determine proper placement of animplant in real-time following implant extraction.

In an embodiment, referencing FIG. 1, the position data of originalfemoral stem 5 that is to be removed can be collected and used forreconstruction of the joint, following extraction of femoral stem 5.This data will guide placement of the revision components to eitherrecreate or correct the original joint mechanics. In such an embodiment,and with respect to hip revision procedures, coupler 10 would mate totrunnion 20 to establish a fixed relationship between positioning system15 and femoral stem 5. The initial hip mechanics/parameters would bedetermined prior to implant extraction based on reference markers90/coupler 10 relationship. This is performed by placing bone referencemarkers 90 in the bones prior to affixing coupler 10 and positioningsystem 15 to femoral stem 5 for use in extraction of femoral stem 5.Bone reference markers 90 are used to reference the position of originalfemoral stem 5 (before extraction) in relation to the bones (e.g., femurand acetabulum/pelvis) and can register the original joint parameters(e.g., hip vertical position, leg length, medial offset, center ofrotation) in centralized computing system 45. Bone reference markers 90may be localized by centralized computing system 45 virtually via probe95 or by transmitter 85. In an embodiment, transmitter 85(accelerometer/gyroscope, visual array for line of sight tracking, etc.)is attached to bone reference marker 90 to provide real-time positioningdata of the bones to centralized computing system 45. This allows fortriangulation with positioning system 15 and coupler 10 to providereal-time positioning and orientation data of femoral stem 5 in relationto the bones. Transmitter 85 uses the same positioning technology asused in positioning system 15. Transmitter 85 and reference marker 90may be separate units. Alternatively, transmitter 85 may be integratedinto reference marker 90. After the bone reference markers 90 areregistered and data collected on the original femoral stem 5 andprocessed by centralized computing system 45, the implant extraction canoccur, as described above.

Once original femoral stem 5 is removed, the new revision femoralcomponent (not labeled) can be placed and coupler 10 and positioningsystem 15 can be attached to the new femoral stem (or trial stem/broach)in the same manner as for extracted femoral stem 5. The bone referencemarkers 90 remain in the bone and can then be used as data referencepoints to reconstruct the joint parameters with the revision implants.This aids in placement of the revision implant components with real-timefeedback on important joint replacement parameters in comparison tooriginal femoral stem 5 (e.g., vertical height, leg length, offset,anteversion, etc. in hip applications. This real-time feedback onimportant joint replacement parameters allows the surgeon to adjust themodular features of the implants needed to correct the joint parametersprior to trialing the construct. For example, in hip revision surgerythe new femoral revision component (not labeled) can be placed in thebone and the coupler 10/positioning system 15 can then be attached tothe component trunnion 20 (trial or final) and register the center ofrotation (which would also account for offset, leg length) againstreference markers 90. If, for example, the centralized computing system45 found the revision components' new center of rotation position toresult in a construct that is 3 mm short in leg length and offset fromthe original extracted femoral stem 5 center of rotation position, thesurgeon would immediately know the specific modular head needed to movethe new center of rotation to recreate the original hip mechanics priorto reducing the hip and trialing the construct. This system would workwith the same accuracy and precision even if an osteotomy was utilizedto extract femoral stem 5 prior to reconstruction.

Utilizing this system for the placement of revision femoral component(not labeled) may utilize robotic arm 50 to help place the revisionfemoral component, whereby robotic arm 50 prepares the bone usingcutting tool 55 (e.g., a pneumatic broach, reamer, burr, chisel, etc.)to match the templated/desired revision femoral component (not labeled)and robotic arm 50 is then attached to the insertion point of therevision femoral component, whereby robotic arm 50 inserts femoral stemusing an insertion tool (e.g., a pneumatic inserter, manual impactionwith robotic assist etc.) to desired position based on the spatialrelationship between reference markers 90, coupler 10, and positioningsystem 15. Coupler 10 could be attached during robotic arm 50 insertionof new revision femoral stem (not labeled) or attached immediately afterinsertion to determine implant position/joint mechanics. Alternatively,the bone can be prepared manually and the implant may be placed manuallyby the surgeon without the use of robotic arm 50, whereby the surgeonuses positioning system 15 and coupler 10 now attached to new revisionfemoral component (or placed on new revision femoral component afterimplantation) and manually inserts the implant (or trialcomponent/broach) prior to referencing its position as described above.

In another embodiment, in reference to FIG. 2., bone reference markers90 may be attached to the pelvis to help guide placement of new revisionhip cup (not labeled) after extraction of original hip cup 60.Additionally, bone reference markers 90 can serve as a reference point,designating hip center on the pelvis. Reference markers 90 may beanchored to the patient's bone. Alternatively, in reference to FIGS.1-2, reference markers 90 may be a superficial registration point, e.g.,an EKG lead patch placed on the skin, to serve as a reference point tojudge leg length, for example.

In another embodiment, referencing FIGS. 3-4, this application can alsobe applied to implant placement in revision surgical proceduresfollowing extraction of the implants in total knee revision procedures.Coupler 75/105/positioning system 15 would mate, as described above tototal knee femoral component 80 and/or total knee tibial component 100to establish a fixed relationship between positioning system 15 on totalknee femoral component 80 and total knee tibial component 100 (eachindependently or in conjunction) with bone reference markers 90.Reference markers 90 would be placed in the femur and tibia bones andregistered. The initial static knee mechanics/parameters would bedetermined prior to implant extraction based on reference marker90/coupler 75/105/positioning system 15 relationship. The centralizedcomputing system 45 determines the position of the original implantcomponent's joint line, extension/flexion gaps, etc. This may or may notinclude additional reference points (e.g. epicondyles, etc.) asidentified virtually with probe 95 to increase accuracy prior toextractions. Alternatively, or in addition, dynamic ligamentous tensionand gap balancing could be determined without couplers 75/105 attached,or prior to attaching couplers 75/105, with only reference markers 90 inplace during knee range of motion/ligament/gap balance testing. This ismeasured by the surgeon performing a range of motion, ligament stresstest, etc. with reference markers 90 affixed to the femur and tibia torecord the dynamic data of the knee joint (e.g. flexion/extension gapduring range of motion, hip center of rotation, ligament tension, etc.)Once static and dynamic data is calculated by centralized computingsystem 45, in conjunction with or without fluoroscopy templating, theoriginal implants total knee femoral component 80 and total knee tibialcomponent 100 are excised as described above in the implant extractiontechnique. In an embodiment, the extraction process could also use thedata collected on original total knee femoral component 80 and originaltotal knee tibial component 100 to guide bone preparation for the newrevision components (not labeled) as part of the extraction process. Asan example, in current techniques the femoral bone must be cut/preparedto fit the new revision total knee femoral component followingextraction of original total knee femoral component 80. In the presentinvention, centralized computing system 45 (knowing static and dynamicdata regarding original total knee joint mechanics and position of totalknee femoral component 80/total knee tibial component 100 againstreference markers 90) could guide robotic arm 50 and cutting tool 55 toprepare the bone to accept the new revision total knee components aspart of extraction. For example, if an additional distal femoral 4 mmaugment on the new total knee revision femoral component would beplanned to recreate the joint line, robotic arm 50 and cutting tool 55could cut an additional 4 mm of bone (behind original total knee femoralcomponent 80) which would simultaneously allow for extraction oforiginal total knee femoral component 80 and preparation of bone for newimplant placement. The ability to simultaneously extract the implant andprepare the bone for reconstruction with new revision implants wouldsignificantly increase the efficiency of the reconstruction process aswell as increase accuracy and precision. As one can imagine, thisapplication for simultaneous reconstruction would work for both the newrevision femur and tibial components (not labeled) and augments in allpositions (e.g., posterior femoral condyles, tibial augments, distalfemoral augments, etc.) as well as specific component parameters (e.g.,rotation, flexion of femoral component, tibial component slope, etc.)Once the implants are extracted, robotic arm 50 could also be used(based on the above data) to prepare the canal for a broach and/or stemattachment(s) to new revision components (e.g., reamers, pneumaticbroach inserter, etc.) as depth of insertion for a broach or stem couldbe determined based on original joint line data collected prior toextraction of original total knee femoral component 80 and total kneetibial component 100. The reference markers 90 are kept in the bonethroughout the process of extraction and reconstruction, as are anyadditional reference points identified by probe 95, and are used by thesurgeon to obtain real-time feedback at the time of reconstruction onthe knee parameters (e.g., joint line reconstruction, gap balance,augment thickness/location required, polyethylene thickness, etc.). Thisallows for accurate positioning of the new revision femoral component(not labeled)/ new tibial revision component (not labeled), which can betrial or final components, in relation to the original implant componentposition/joint parameter data collected. The accuracy of the jointreconstruction with the revision components can then be assessed byreattaching couplers 75/105 and positioning system 15, respectively, tothe new revision components to reference against the bone referencemarkers 90 upon insertion (to check static parameters) and prior totrialing the new revision components (dynamic parameters). If extractionoccurred without specific robotic arm 50 bone preparation to matchplanned new revision components and bone is prepared via traditionalmethods (e.g., cutting blocks affixed, intramedullary rods, etc.),additional reference points as defined by probe 95 after extraction maybe required (e.g., to re-register (“paint”) the location of theremaining femoral bone/tibia against the reference markers 90 placedbefore extraction of the implant). This would facilitate more efficientselection of augments for cutting blocks for bone preparation and forthe correct femoral modular component selection (e.g., femoral size,augments, etc.) and tibial modular component selection (e.g., tibialaugments, polyethylene insert thickness) needed to recreate or correctthe original total knee mechanics prior to extraction. The knee can thenbe more efficiently trialed. During trialing coupler 75/105 may beremoved and dynamic joint data (ligament tension, gap balancing, etc.)can be obtained with reference markers only 90 as performed prior toextraction.

The flow chart depicted in FIG. 6 summarizes the method of jointreplacement implant placement following implant extraction using thepresent system. The method outlined in FIG. 6 can be applied to anyjoint implant component and is provided for illustrative purposes,according to an embodiment of the present invention. Therefore, itshould not be interpreted as being limiting to any particularapplication

Primary Hip Replacement Femoral Component Insertion

In an embodiment, with reference to FIG. 1, the present invention canalso be applied to implant placement in primary hip replacement surgicalprocedures.

In this embodiment, no extraction is needed so cutting tool 55 will notbe used to excise a component. However, cutting tool 55 may be used toprepare the bone for implant placement as described below. In thisembodiment, an x-ray/fluoroscopic image of the joint is takenintraoperatively for real-time templating purposes. When utilizing anintraoperative film or fluoroscopy, one or more reference markers 90 areattached to the patient in the area to be imaged prior to taking theimage. In one embodiment, the reference markers 90 are attached to theproximal femur as a cortical button and are calibrated (knowndimensions) to aid in scaling for templating by centralized computingsystem 45 and allow for determining the native hip center of rotationposition in relation to reference markers 90. In another embodiment,reference marker 90 may be a superficial registration point, e.g., anEKG lead patch placed on the skin, to serve as a reference point tojudge leg length, for example. Superficial registration points areoften, but not always, used in conjunction with advanced imaging, e.g.,a CT, Mill, or EOS scan. Based on information transmitted from theradiographic image/template/reference marker 90 scaling and position ofthe native hip center of rotation, centralized computing system 45 cancalculate/template the joint, e.g., the hip, and also can use theopposite joint, i.e., the opposite hip, as a reference to comparedifferences between the two joints. With this information, referencemarker 90 can then be checked at the time of insertion of femoralcomponent 5. This is done, for example, by placing probe 95 on thecortical button, i.e. reference marker 90, whereby computing system 45determines the position of femoral stem 5 center of rotation, as definedby coupler 10 and positioning system 15 attached to femoral stem 5trunnion 20 as described above, as referenced against the referencemarker 90. Alternatively, if the transmitter 85 is built into thereference marker 90, probe 95 may not be required since the referencepoint would register immediately in real time. Thus, the surgeon candetermine, real-time what adjustments are made and, hence, what exactfurther adjustments need to be made to recreate the native hipmechanics, center of rotation, offset, and leg lengths. For example, thesurgeon would know immediately whether a particular adjustment changedthe center of rotation and lengthened, shortened, increased offset,decreased offset, or altered version of the joint's associated anatomy.Additionally, centralized computing system 45 can instruct the surgeonon what implant (e.g., modular head adjustment, adjust implantplacement, etc.) to use to accomplish the appropriate correctivemeasures. For example, centralized computing system 45 can determinewhat modular femoral head/neck length is needed to restore theappropriate leg length/anatomy/offset, etc., based on the initialx-ray/template and utilizing the spatial relationship (i.e.,triangulation) between reference markers 90, coupler 10, and positioningsystem 15. Coupler 10 and positioning system 15 construct may alsoconnect to a broach or trial implant (not shown) to provide the samereal-time information on seating of the broach or trial implant prior toplacement of final implant femoral stem 5.

By providing real-time analysis, positional and orientation data of theimplant, etc., during the seating process of the implant, or immediatelyafter seating, e.g., femoral stem 5, the surgeon is able to determine,without interruption and with absolute precision and accuracy, whatadjustments must be made for proper seating of the implant. The systeminstructs the surgeon with real-time feedback on leg length, stemseating height within the femur, and position of femoral stem 5 inrelation to the pre-op plan/component position/reference markers 90desired by the surgeon. This facilitates more efficient selection of thecorrect size broach/trial stem, final femoral stem as well as themodular femoral head required to correct leg length and offset based onthe position of femoral stem 5. The real-time information of femoralstem 5 provides the exact vertical height, offset and the femoralanteversion of femoral stem 5 so the surgeon can make adjustments, asneeded, based on intraoperative findings and with comparison to thetemplate to restore the desired hip mechanics/parameters, therebysignificantly reducing the risk of placing femoral stem 5 in varus orunder-sizing the component and mitigating the risk of intraoperativefracture as well as decreasing the risk of dislocation. In addition toensuring proper placement of the implant, the need for intermittentscans is obviated, reducing overall procedure time andx-ray/fluoroscopic exposure to the patient and surgical team.

Utilizing this system for the placement of primary femoral stem 5 mayemploy robotic arm 50 to help place femoral stem 5, whereby robotic arm50 prepares the bone using cutting tool 55 (e.g., a pneumatic broach,reamer, burr, chisel, etc.) to match templated/desired revision femoralcomponent (not labeled) and robotic arm 50 is then attached to theinsertion point of femoral stem 5, whereby, robotic arm 50 insertsfemoral stem 5 (e.g., using pneumatic inserter, etc.) to desiredposition based on the spatial relationship between reference markers 90,coupler 10, and positioning system 15. Coupler 10 could be attachedduring robotic arm 50 insertion of femoral stem 5 or attachedimmediately after insertion to determine implant position/jointmechanics. Alternatively, the bone can be prepared manually, withoutrobotic assistance, and the implant may be placed manually by thesurgeon without the use of robotic arm 50, whereby the surgeon usespositioning system 15 and coupler 10 now attached to new femoral stem 5and manually inserts femoral stem 5. Referencing its position againstreference markers 90 as described above. Alternatively, coupler 10 andpositioning system 15 can be attached after femoral stem 5 has beeninserted.

The flow chart depicted in FIG. 7 summarizes the method of implantplacement in primary hip replacement surgical procedures using thepresent system. The method outlined in FIG. 7 is provided forillustrative purposes, according to an embodiment of the presentinvention. Therefore, it should not be interpreted as being limiting toany particular application.

The foregoing descriptions regarding various joint revision or primaryimplant procedures is provided for illustrative purposes only, and isnot meant to limit the scope of the invention to any particularapplication. One skilled in the art would understand and appreciate thatthe invention could be similarly applied to other joint revision orprimary implant procedures other than those specifically described(i.e., the present invention can be used with any joint that is acandidate for primary replacement or revision surgery in any applicationdescribed herein) without deviating from the scope of the presentinvention. As long as there is an anchor, e.g., a trunnion, a threadedaperture/orifice, etc., that is fixed in space, relative to theprosthetic component to be seated or removed, and can serve as aconnection point to, likewise, fix the positioning system in space, in aknown relationship, relative to the prosthetic component to be seated orremoved, the present invention can be used to identify the exactreal-time position and orientation of a prosthesis in any jointreplacement, i.e., primary or revision, surgery.

The invention has been described herein using specific embodiments forthe purposes of illustration only. It will be readily apparent to one ofordinary skill in the art, however, that the principles of the inventioncan be embodied in other ways. Likewise, it will be readily apparentthat the features, functions, and/or elements of the present inventiondisclosed herein can be used in any combination to produce variousembodiments of the present invention. Therefore, the invention shouldnot be regarded as being limited in scope to the specific embodimentsdisclosed herein, but instead as being fully commensurate in scope withthe following claims.

I claim:
 1. A system for extracting and placing joint implantscomprising: a. a centralized computing system; b. a joint templatingsoftware program configured to compare joint scans with overlayschematics of an implant component; c. a CAD software program configuredto analyze a computer-generated design of the implant component, whereinthe joint templating software program and the CAD software program areexecuted on the centralized computing system; and d. an implantlocalization device in communication with the centralized computingsystem, the implant localization device comprising: i. a coupler; andii. a positioning system comprising one or more sensors in communicationwith the centralized computing system, wherein the coupler is configuredto removably engage the implant component to fix the positioning systemin space relative to the implant component, wherein a real-time positionand orientation of the positioning system is determinable by thecentralized computing system, based on data from the positioning system,wherein the centralized computing system is configured to calculate areal-time position and orientation of the implant component, based onthe real-time position and orientation of the positioning system,wherein the centralized computing system is configured to synthesizedata from the joint templating software program, the CAD softwareprogram, and the positioning system to provide real-time data to assistwith extraction and placement of the implant component.
 2. The system ofclaim 1, wherein a starting position and orientation of the positioningsystem is registered with the centralized computing system, wherein thecentralized computing system is configured to use real-time data fromthe positioning system to determine changes in position and orientationof the positioning system, relative to the starting position andorientation of the positioning system, thereby allowing the computingsystem to calculate a real-time position and orientation of thepositioning system.
 3. The system of claim 1, further comprising arobotic arm in communication with the centralized computing system,wherein the centralized computing system is configured to determine areal-time position and orientation of the robotic arm relative to thereal-time position and orientation of the implant component, wherein therobotic arm is configured to execute instructions received from thecentralized computing system, wherein the instructions are based oninformation comprising the synthesized data and a real-time spatialrelationship between the robotic arm and the implant component.
 4. Thesystem of claim 3, wherein the robotic arm comprises a cutting toolconfigured to facilitate extraction of the implant component.
 5. Thesystem of claim 3, further comprising one or more reference markers,wherein the one or more reference markers are registered with thecentralized computing system, wherein the centralized computing systemis configured to determine a real-time position and orientation of theone or more reference markers relative to the real-time position andorientation of the implant component and the robotic arm, wherein theinformation further comprises the real-time position and orientation ofthe one or more reference markers relative to the real-time position andorientation of the implant component and the robotic arm.
 6. The systemof claim 5 wherein the robotic arm comprises an insertion toolconfigured to facilitate placement of the implant component.
 7. Thesystem of claim 5, further comprising a probe configured to register theone or more reference markers with the centralized computing system,wherein the centralized computing system is configured to analyze areal-time position and orientation of the coupler relative to thereal-time position and orientation of the one or more reference markersto determine real-time joint parameters of the implant component.
 8. Thesystem of claim 1, wherein the coupler is selected from the groupconsisting of a sleeve, a clamp, and a rod.
 9. The system of claim 1,wherein the positioning system is integrally formed as part of thecoupler.
 10. The system of claim 1, wherein the positioning system isremovably coupled to the coupler.
 11. The system of claim 1, wherein thepositioning system comprises at least one of an accelerometer and agyroscope.
 12. The system of claim 1, wherein the positioning systemcomprises a sensor array.
 13. The system of claim 1, further comprisinga database of implant component designs, wherein the database comprisesthe computer-generated design.
 14. The system of claim 1, furthercomprising a probe in communication with the centralized computingsystem, wherein the probe is configured to register virtual referencepoints on the implant component, wherein the CAD software program isfurther configured to extrapolate contour and dimension data of theimplant component, based on the virtual reference points.
 15. An implantlocalization device comprising: a. a coupler; and b. a positioningsystem, wherein the coupler is configured to removably engage an implantcomponent to fix the positioning system in space relative to the implantcomponent, wherein the positioning system is configured to communicatewith a computing system, wherein a real-time position and orientation ofthe positioning system is determinable by the computing system, based ondata from the positioning system, wherein a real-time position andorientation of the implant component is determinable by the computingsystem, based on the real-time position and orientation of thepositioning system.
 16. The device of claim 15, wherein the coupler isselected from the group consisting of a sleeve, a clamp, and a rod. 17.The device of claim 15, wherein the positioning system is integrallyformed as part of the coupler.
 18. The device of claim 15, wherein thepositioning system is removably coupled to the coupler.
 19. The deviceof claim 15, wherein the positioning system comprises at least one of anaccelerometer and a gyroscope.
 20. The device of claim 15, wherein thepositioning system comprises a sensor array.